<!DOCTYPE html>
<html style="height: 100%">
  <head>
    <script>
      function doIt() {
        var d = document.createElement("div");
        d.setAttribute("style",
                       "position: absolute; left: 0; right: 0; top: 0; " +
                       "bottom: 0; background: green");
        document.getElementById("x").appendChild(d);
      }
    </script>
  </head>
  <body style="height: 100%" onload="doIt()">
    <table style="height: 50%; width: 50%">
      <tr>
        <td id="x" style="position: relative; top: 25%; left: 25%">
        </td>
      </tr>
    </table>
  </body>
</html>
